The present invention relates to a temperature controlling method and apparatus for a refrigerator in which temperature of a refrigeration compartment is evenly controlled by precisely discharging cool air into a position to be cooled according to the distance from a rotary blade thereto by a fuzzy inference and the learning by a neuron network.
Generally, since the load of the items being refrigerated is different at different portions of the refrigeration compartment in a refrigerator, particularly, in a large refrigerator, it is difficult to evenly maintain temperature within the refrigeration compartment. Accordingly, research into a method for evenly controlling the temperature of the refrigeration compartment has been performed as the storage capacity inside the refrigerator increases. In one such method, the discharge of cool air is controlled by rotating a rotary blade attached to the rear wall of the refrigeration compartment. Here, the cool air is discharged into a high-temperature portion to even out the temperature within the refrigeration compartment. The rotary blade determines a cool air discharge direction according to its stationary position (a predetermined stationary angle) or continuously rotates at a constant velocity to discharge cool air like a ventilation fan.
However, since the ventilation force by the rotation of the rotary blade is constant in a refrigerator having the rotary blade, the discharge of cool air cannot be controlled according to the distance from the rotary blade to a target area to be cooled. In other words, when intending to discharge cool air to a front portion of the refrigeration compartment, far from the rotary blade, the rotation velocity of the rotary blade should be increased to discharge the cool air into the front portion. Meanwhile, when intending to discharge cool air to a rear portion of the refrigeration compartment, near the rotary blade, the cool air discharging velocity should be reduced by rotating the rotary blade at a low velocity or stopping the rotation of the rotary blade altogether. However, the conventional rotary blade cannot appropriately control the cool air discharging velocity due to the constant rotation velocity thereof.
Also, as a precondition for controlling the cool air discharging velocity through the controlling of the rotation velocity of the rotary blade, temperatures of each portion should be precisely measured according to the distance from the rotary blade to each portion. However, in the conventional refrigerator having only two temperature sensors positioned at upper and lower portions of the refrigeration compartment, it is difficult to precisely measure the temperatures of each portion. Also, even though the temperatures of each portion are inferred by the fuzzy inference to some degree of accuracy, the conventional refrigerator cannot correct specific errors of every product, which may occur during the mass production thereof, so that there are limitations to the accuracy of the inference.